“Simply stated, I need it.” I really can’t do without it, because I have many projects that I am still paid to support and to enhance which were built using this rendering technology. I’m frankly not willing to accept that I cannot enjoy the benefits of 2.80-and-beyond with regards to these “legacy” projects.
I’ll also suggest that – now that BI has been cleanly removed from the code-base and all of the loose-ends have been tidied up, it might well now be much easier to re-introduce this renderer in a new and much-cleaner way. (For instance, when you switch to this renderer-type in your project, controls in the user interface can switch implementations, and the selection of other controls and menu-items can change also.)
If you can introduce something as “marvelously new” as Eevee, you can also make-over something that is [still …] “marvelously old” but still needed by your customers, making it better and cleaner than it ever was.
Even though Blender quite-rightly says that renderers such as Eevee and Cycles are “better,” there are many thousands of existing Blender projects out there – many of them revenue-producing – that simply can’t be left behind. We still need to produce those same outputs for our clients, and to work with all those hundreds of files, and we shouldn’t have to be “stuck in the past” to continue to do so.
(Feel free to build logic that will re-save the files in a “not backward-compatible” way, and to re-imagine BI operations in a manner consistent with the new metaphors that you have introduced. Just give me a way to continue to use this render engine.)
Furthermore, I would argue that the rendering principles embraced by BI are still just as “valid” as they ever were.
I’m entirely confident that the Blender developers can find a way to achieve this, once they again put their minds to it. And, I have a business($$) need for it that will not go away anytime soon.